The goal of this investigation is to describe familial clustering of suicidal ideation and attempts. Secondary analysis of an existing community-based survey will address three major objectives. First, to estimate the prevalence of family history of suicide attempt(s) and to describe its distribution in the population. Second, to assess the role of family history of suicide attempt(s) as a risk factor for self-report of suicide ideation or attempt. And third, to identify characteristics that differentiate whether those with a family history of suicidal acts self-report suicidal thoughts or acts of their own. This research is significant because the belief that suicide "runs in families" has not been tested previously in a community-based sample unbiased by selection factors. Standard statistical techniques will be used to address the major objectives. Analyses will be based on interview data collected between 1983 and 1985 at the Los Angeles site of the Epidemiologic Catchment Area program (LA- ECA). The sample includes both community and institutional adult respondents. The community sample is comprised of Mexican Americans (N=1,244), non-Hispanic whites (N=1,310), and other racial and ethnic groups (N=578). The institutional sample includes 511 residents of prisons, psychiatric and substance abuse treatment facilities, board and care homes, and nursing homes. The self-report suicide-related questions are drawn from the Diagnostic Interview Schedule, which was used to collect the information necessary to generate DSM-III diagnoses. Suicidal acts by family members (mother, father, siblings, children) are obtained from questions specific to the Los Angeles site.